/**
 * Copyright 2019 Anthony Trinh
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package ch.qos.logback.classic.pattern;

import ch.qos.logback.classic.spi.ILoggingEvent;

public class RelativeTimeConverter extends ClassicConverter {

  long lastTimestamp = -1;
  String timesmapCache = null;

  public String convert(ILoggingEvent event) {
    long now = event.getTimeStamp();

    synchronized (this) {
      // update timesmapStrCache only if now !=  lastTimestamp
      if (now != lastTimestamp) {
        lastTimestamp = now;
        timesmapCache = Long.toString(now - event.getLoggerContextVO().getBirthTime());      
      }
      return timesmapCache;
    }
  }
}
